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<head>
    <meta charset="UTF-8">
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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        Array.prototype.qc = function(){
            return this.sort(function(a,b){
                return a - b;
            })
        }

        var test = [1,3,5,6];
        var res = test.qc();
        console.log(res);
    </script>
</body>
</html>